


iNVaDeR FeLL: The Nightmare Begins

by Kamari333



Category: Invader Zim, Undertale (Video Game)
Genre: Background Professor Membrane (Invader Zim)/Underswap W. D. Gaster (Undertale), Dib (Invader Zim) & Underswap Papyrus & Underswap Sans (Undertale), Dib (Invader Zim) & Underswap Papyrus (Undertale), Implied/Referenced Character Death, Oblivious Professor Membrane, Other, Other Additional Tags to Be Added, Parent W. D. Gaster, Scientist W. D. Gaster, The Almighty Tallest Being Assholes (Invader Zim), Underfell Papyrus (Undertale), Underfell Papyrus/Underswap Papyrus (Undertale), Underswap Papyrus (Undertale), Underswap Sans (Undertale), Zim (Invader Zim) & Underfell Papyrus (Undertale)
Language: English
Status: Completed
Published: 2021-03-07
Updated: 2021-03-09
Packaged: 2021-03-14 01:07:26
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 4
Words: 12,684
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29909820
Author URL: https://archiveofourown.org/users/Kamari333/pseuds/Kamari333
Summary: 3rd Prize for the 333 Twitter Follower Fic Raffle.A Crossover between the universe of Invader Zim and the multiverse of the Undertale AU fandom.Shit gets crazy when you shove two very different fandoms together and try to make something out of it.
Relationships: Dib (Invader Zim) & Papyrus & Sans (Undertale), Dib (Invader Zim) & Papyrus (Undertale), Papyrus (Undertale) & Zim (Invader Zim)
Comments: 31
Kudos: 10
Collections: Kamari333 Gifts and Prompts





	1. Operation Impending Doom II

**Author's Note:**

  * For [MsMK](https://archiveofourown.org/users/MsMK/gifts).



> I had _way_ too much fun writing this. too much fun. Thank you so much MK for requesting this absurd, whimsical mess of a guilty pleasure <3 i hope you like it <3
> 
>  **For those of you coming in from the Undertale fandom:** I just wanna say I'm so sorry for subjecting you to Invader Zim nonsense. It is such a good show (and comic series) in my opinion, but the humor and themes are so very different than what you might be used to, and certainly aren't for everyone.
> 
>  **For those of you coming in from the Invader Zim fandom:** I just wanna say I'm so sorry for subjecting you to Undertale multiverse nonsense. If you aren't familiar with the game, names and themes may just throw you entirely for a loop. And... even if you _are_ familiar with the game... If you aren't familiar with the batshit crazy rabbit hole that is the Undertale Alternate Universe community, you might _still_ be lost. I have very much tried to write this so that previous knowledge of these concepts aren't strictly necessary (especially since i've taken it in a different direction anyway), but it may still not hit right for you.
> 
> The Undertale fandom is my special interest though, so I might be bias in saying that, craziness aside, it's wonderful and fun, and i hope you enjoy your glimpse of it as you visit
> 
> I also want to apologize because this is my very first time ever writing for the Invader Zim fandom, and even though i rewatched the series again (and started reading the comics) to freshen up on characterization, themes, and tone, (as well as outright ripping dialogue because gotta hammer in where things change by showing where things stay the same lol) I doubt very much I can ever do the story justice.
> 
>  **No matter where you come from:** I wanna than you so much in advance for giving this indulgence a shot. thanks so much for reading! i know crossovers are a whole Thing ™ and not everyone enjoys them, but thank you for trying this one out! <333
> 
> Please forgive the weird tags- Undertale AU tags are just Like That and I'm new to tagging Invader Zim.
> 
> Also thanks to yall who read this whole ass A/N i know long ones are boring <333

**Summary for the Chapter:**

> The Fell-Irken Empire sends Invader Edge and Prince Zim to Earth during OID2.
> 
> Nobody is happy with this except Zim and the Almighty Tallest.

**Notes for the Chapter:**

> A lore establishing chapter to show how the Irken Empire and the Underfell AU are interacting, what the hierarchy is, what the relationships are, and who Underfell Papyrus (nicknamed Edge for simplicity) really hates the most.

The Irken Empire (which had retained its name even after the shift in management brought about by the events of Operation Impending Doom I) was more alive than it had been in years. Signs replayed message after message redirecting convention-goers how and where to attend the Great Assigning in the Main Convention Hall on Conventia, one of the many planets conquered and repurposed for the good of the Empire. The teleporter ring was blazing almost as brightly as it once did before OID1, only this time, it brought to the surface not _Irkens_ , but _Monsters_ ; creatures of every shape and size. They came not only from the 'kingdom' that had overtaken Irk (they called themselves 'Fell'), but those from the 'kingdoms' of conquered worlds as well, which had been expeditiously subjugated in a fashion worthy of the Irken Empire.

Almighty Tallest Red might have been intimidated as he watched them pour into the convention center from the back room, arms crossed as he stood before the monitors. Many of the Monsters were much taller than even himself and his co-ruler (and 'brother', a word that tasted foreign on his tongue) Purple. Size or no size, however, Red was secure in his position of leadership. If anything, he was even more untouchable than before. The only real difference between 'now' and 'how it used to be' for Red was that, instead of Control Brains, the only ones with authority to overrule his word were his new 'parents' (another foreign word), and neither Toriel nor Asgore seemed to have any interest in denying him _anything_. No snack was too succulent, no power too irresponsible to wield, no whim too short-sighted.

Watching 'dad' execute one of his own loyal followers, simply because Red didn't want to share a name with such a short, tiny creature, had been a thrill that Red didn't know he could feel. His species was nearly extinct, his home planet overrun by beasts only spoken of in the most fantastical of nightmares, and Red was _loving it_.

Purple chowed down on one of the many snacks hand-baked by their new 'mom', a rather large butterscotch-cinnamon pie that sparked and bubbled with 'magic' (another novelty in their new lives that Red had to admit was an improvement -- it even took care of the headaches Purple and their other 'sibling' tended to generate by their mere existence). Halfway through the dish, Purple pulled a gooey chunk out of the tin and offered it to one of the others in the room. "Want some?" He asked with his mouth full of delicious butts-pie.

Undyne, their personal bodyguard (a Monster with iridescent blue scales and a thick mass of flaming red tendrils protruding from her head where antennae should have been), recoiled with a disgusted sneer. "No, thank you." Her response was tight, restrained, barely making it past her needle-sharp teeth. She hadn't been particularly 'friendly' with either of them since the execution (not that it mattered as long as she obeyed, which she did).

"More for me," was Purple's reply, eating the pie chunk himself.

The only other person in the room looked up from his data pad, using one of many disembodied hands to set the device on one of the tables. "Your majesties-"

"HUH?!" Purple demanded, purposefully interrupting the Monster.

Gaster stared back, his pale, broken face unimpressed and impassive.

"Who?" Red asked, demanded, quirking up one of his antenna in the creature's direction. It was still unsettling to have to look up to meet someone's eyes, nevermind stare into eyes that were more hologram than flesh. Looking at Gaster still made Red's squeedlyspooch clench and twist inside him, but like hell Red would ever willingly show that.

Gaster stood eerily still for a long moment, then his expression shifted to one of distain. The glowing pips in his orbital sockets rolled along the upper ridge in a gesture that Red had begun to associate with sweet, sweet victory. " _My Tallest_ ," Gaster corrected (and _oh,_ did it feel a different kind of _good_ to hear those words from someone who was so fucking tall), "the Convention Hall has reached maximum capacity. Everything is prepared as per your... _exacting_ requests."

"It better be," Red warned, making his way to the platform . He didn't care if Gaster was the precious 'royal scientist' or not: if the man couldn't rig a decent laser light show, he was useless to him.

It wasn't smart to be useless to Almighty Tallest Red.

* * *

The announcer heralded their descent. Red waved at the crowd of silent, stoic beasts. He had expected cheers, rabid screaming in his name. Instead, they all stood at cold, stiff attention, various appendages held aloft or against torsos or foreheads in what Red had come to recognize as a formal gesture of respect. The laser show was amazing, flashing off around them, but no one batted an eye.

In stark contrast to the eerie silence, the air trembled as if Red were surrounded on all sides by huge loudspeakers blaring directly onto his poor, sensitive antennae. It was a feeling he wasn't yet adjusted to, the feeling of energy monsters tended to emit just by breathing, by existing; ultrasonic and infrasonic waves clashing and harmonizing in patterns almost like music, like screams. Having so many different 'voices' all at once was nearly overwhelming.

" _Told you_ smoke machines were the way to go," Purple whispered, reveling in undeserved smugness.

"You don't know that. They're probably just dumb and boring." Monsters weren't any fun. Red supposed he would have to teach them how to greet their Tallest _properly_ another day.

"Lasers are just stupid, and you're mad I was ri- OH DAMNGHAAAAA!" Purple clutched at his ocular implants, flinching backwards and falling prone on the platform as he screamed in pain from having a laser beam shot directly into his eye.

Red smiled as he heard a few startled laughs come from the crowd. At least _some_ of them had a sense of humor.

The platform settled. Red waited a breath, milking the suspense, before speaking. "Welcome, mighty soldiers of the great Irken Empire!" Not a one of them was a true Irken, but that would change. There would be new smeets, new soldiers; Red just had to wait, to prepare. "You are the finest examples of military training the Irken Army has to offer! Good for you."

There was still that silence, that overpowering wall of _presence_ from all sides. Someone sneezed.

Red gestured to the stiff, militant row of individuals lined up behind the platform as Purple finally dragged his body off the ground. "Standing behind us, however, are the soldiers we've chosen for roles in one of the most crucial parts of Operation Impending Doom II!"

On cue, the holographic jumbo screen displayed the stellar map that had been plotted for Irken-Fell conquest. The silent pressure intensified around Red, as if the air itself had become excited. Red was starting to like it. "You in the audience just get to sit and watch."

"You should have tried harder," Purple added. Which was true. They should have.

Red again gestured to the chosen invaders. "These superior ones-"

"Not quite as superior as us, of course!"

Red sneered, just stifling a laugh at the very idea. "Duh! These _less superior than us_ , but still _quite_ superior soldiers, will each be assigned to an enemy planet!"

Purple circled behind Red, directing his attention to the chosen elite. "There you will blend in with the hideous, native inhabitants!"

"All while gathering crucial information, assessing the planet's weaknesses, making it vulnerable to our big-" Red mentally stumbled, the word he was looking for eluding him completely. "Spaceship-!!" He tried to grasp for it, gesticulating as if that would conjure the word he wanted, but damn if it seemed like he had lost the vocabulary altogether. He chalked it up to a malfunction in his PAK, and made a mental note to have Gaster look at it later. Or maybe the mechanic drone, Alf? Whatever its name was. It was always fun to bully. "Gang!" There, that worked, fuck it.

"The _armada_ ," Purple corrected, leveling Red with an unimpressed deadpan, like he had any room to be disappointed when Purple forgot where they left their snacks all the time and couldn't open the marshmallow bag without ripping it. "Now..."

Purple struck a pose, arms raised up as he projected his voice. "Let the Assigning begin!!"

Still the silence persisted, but the air was alive, breathing, screaming.

Red could get used to this.

* * *

Edge stood at stiff attention, keeping his gaze forward, hands clasped behind his back. He could feel the intent in the air, the mixed feelings their people had for the two scrawny little freaks their monarchy had adopted on a whim. Edge knew where he himself stood, but he kept his hate on a firm leash, his violence and bloodlust under tight control. If there was _any_ luck, _any_ karmic retribution left in the universe, then Asgore would grow bored playing happy family with the 'Irkens', and Edge would be first in line to finish their well-earned extermination.

He would take the greatest pleasure in ripping the still-beating soul out of 'Tallest Red' and crushing it to dusty rouge in his fist.

The royal children continued their loquacious nonsense for longer than Edge thought reasonable outside of a torture room. They went steadily down the line of Royal Guardsmen (even if the 'Tallest' -- a ridiculous name, hardly even accurate given Undyne stood equal and plenty of other Monsters exceeded their stature -- refused to acknowledge their proper rank), starting with Lesser Dog.

The canine's excitement about being initially assigned to hunt the Slaughtering Rat People of Planet Blorch made its neck grow. Edge wasn't sure if the Irken's decision to reassign it to Vort was meant to be the punishment it was, or if they legitimately thought they were rewarding LD for its increased height. All Edge knew was that one of his best guardsmen had been cruelly teased with the chance to hunt rats and had had it ripped away unnecessarily. He added it to his growing mental list of Reasons to Hate Irkens.

Edge largely tuned out most of the other assignments. He had already ordered his men to report to him regularly regardless.

The Irkens skipped over Edge in the lineup. The brief moment when Purple met his gaze gave Edge a taste of fear he would savor for weeks.

Soon enough, Edge was the last left to be called. Purple hesitated, stumbling over his words as Edge caught the sound of a high pitched voice demanding someone (or perhaps many someones), "Get out of my way! Move it! Move it! Get out of my way! Move!! You're in my way!! Get out of my way, get out of my way!! Move it, move it!! You have a big butt!! Move it! Move, move, move!!" When he looked over the Irken's shoulder, Edge could see a wave of bodies shifting in a pattern as a smaller creature wove between legs and other appendages.

Finally, right from below the platform, there came a scream of " _Wait!!_ " As if the words hoped to cut through all the intent in the air, to be heard and acknowledged and obeyed.

"That voice-" Tallest Red gasped, shrinking back a bit from the space.

"It can't be!!" Purple echoed as they all saw a tiny green body heave itself onto the platform.

The tiny green creature lifted its head, and just as Edge recognized the face, the other two Irken scum confirmed it by giving him a name. "Zim."

The air in the room changed. Even if the 'Tallest' were rightfully looked upon with hatred and disdain, Prince Zim had a sort of grudging endearment attached to his name. Everyone knew he was 'defective' (Purple's words, although the exact context of that statement had yet to be explained to Edge), clever in some ways but painfully stupid in others; it was difficult, however, for even the hardened warriors of Fell to dismiss their gratitude to the creature that had freed them from their Underground prison. Of all the Irkens, it was only Zim that Edge would hesitate to destroy.

The look on Edge's brother's face when he saw the stars for the first time; the memory of that was worth the life of a single Irken. It was worth Zim's life.

And if not that, Tallest Red's horror and distaste at the mere sight of Zim would have been enough as well.

Zim closed the distance between himself and the other two, stepping into the spotlight as he caught his breath. "Sorry I'm late, my Tallest, but I couldn't find my invitation! You're lucky I made it at all!"

"You weren't _invited_ at all..!" Tallest Red hissed.

"Aren't you supposed to be at home with- uh- Pie Lady?" Purple asked.

"Oh, I left after I heard about this." Zim waved it off.

"You-" Purple started, stammering in disbelief.

"The Assigning is basically over, Zim," Tallest Red growled. "We don't even _have_ any more planets to assign out. Go home!"

Zim stomped his foot. "You can't have an Assigning without _me!_ I was in Operation Impending Doom I!! Don't you remember?!"

Tallest Red and Purple looked at each other, then out at the crowd of Monsters. Edge could only imagine what they were thinking, what they must have imagined this day was supposed to be like, had Zim not freed them all from their ancient prison and let them loose to decimate their people, as their ancestors had tried to do to them.

"Oh, yes..." Purple growled. "We remember."

Edge remembered the way the ground shook, the smell of smoke and fire, the great crack as the Barrier was broken from the outside, smashed and shattered by the force of a blast it was not meant to withstand on that side. He remembered how the caves echoed suddenly and sharply with screaming, with the rumble of explosions, with the distant peel of maniacal laughter. He remembered how the intercoms spread throughout their tiny, cramped kingdom had blared with orders to evacuate and attack.

Edge remembered the feeling of Irken blood on his hands, the smell of the pink, translucent fluid as it mixed with the dust that clung to his clothes. They splattered like insects when struck. He and his brother had taken to long-range combat to avoid the mess.

He remembered scolding his older brother for raiding a vending machine mid-siege, how he'd had to scream to be heard over the sounds of war, while Red hadn't had to raise his own voice at all. The low, confident drone of his familiar, gravelly baritone still echoed in Edge's skull, as clear as a recording, as if it were being spoken right next to him: "can't win no war on an empty stomach, boss; 'sides, if i eat it, they c _ant_."

Edge felt a lump in his metaphorical throat, which he quickly swallowed, forcing himself back into the present.

"And look!" Zim gestured at the Monsters still in attendance. "Look at the clear improvement! Now we have such majestic creatures to admire the greatness that is Zim!"

Edge felt the approving intent radiate in the air: fool that he was, Zim certainly had the political favor for his role in their freedom. If it was a fight between Zim and the other two, Edge had no doubt who would have the support of the Monsters, and who wouldn't. Edge could see Tallest Red knew it too, enjoying the irritated twitches that spasmed through his antenna with a petty glee.

"Be that as it may, you're an- you're-" Red looked for a word, for something to say that wouldn't tank what little social status he had.

"You're a 'Prince' now, Zim, not an Invader," Purple purred, taking over the conversation where Tallest Red so often failed. "How could we _ever_ send out _dear_ little, teeny, tiny, itty, bitty 'Brother' out on such a dangerous mission~?"

Red perked up. "Y-yes! Yes, just- just think of how terrible it would be if anything happened to you! Think of all the subjects you would disappoint! If you were to go on a mission, why, we couldn't play favorites either! We'd have to hold you up to such impossibly high standards! And it would be dangerous! You might never... return..."

"But-" Zim trembled with emotion. "Invaders blood marches through my veins, like giant _radioactive rubber pants!!_ The pants _command_ me!" He put his hands on his hips, leaning forward as if he could level his gaze with the creature twice his size. "Besides, 'Mom' says you _have_ to let me be an Invader! I am Zim!! Gimme!"

"Hold on," Tallest Red muttered to Purple, "I got a plan." He stepped forward a little closer to Zim. "As it is the will of our great 'Monarchs,' we cannot deny that you are truly deserving."

"Yes." Zim agreed with a straight face. "Yes I am."

Tallest Red continued without missing a beat. "You will be sent to a plant so mysterious, no one has even heard of it."

"Right!" Purple chimed in. "And those who have heard of it, dare not speak it's name."

Edge rolled his eyelights. He knew where they were going with this. Everyone else in the auditorium knew where they were going with this. This wasn't even fucking clever, and the only reason it was going to work was because Zim was so painfully socially inept.

"What's it's name?"

"Oh, I dare not speak it!"

"Where is it?"

Red made long, droning filler noises as he scanned the starmap, until inevitably pointing to a sticky note that had been stuck to the frame on the far side. "Right there!"

"Oooooooh! A _secret mission_..!"

"Happy now?" Tallest Red asked.

"Yes..!" Zim quivered with his unrestrained bloodlust, with malicious delight reflective of his LV (a number so high for such a small, stupid thing).

"And since we can't have our most valuable 'Prince' going off on such a Dangerous Secret Mission without proper reinfocements..." Tallest Red all but purred, before pointing to Edge.

Edge stared at the slender, disgusting appendage, uncertain what the little fucker was even getting at.

"Invader Edge will accompany you as an auxiliary unit!"

Edge felt the metaphorical bottom fall out from under him. He knew what this was. This was _banishment_. This was those two irken scum getting rid of two undesirables with one move, painted over in the guise of public relations and politics. It would be infinitely more difficult for Edge to organize the coup when he was tossed to the outskirts of space, and they _knew_ it.

This fucking idiot, this moronic irken scum, just handed them a way to get rid of Edge _gift wrapped_.

Tallest Red pointed Burgerpants out of the crowd. "You. You're an Invader now. You will be assigned to Blorch, home of the Slaughtering Rat People. All Invaders report to the Equipment Hall! So ends the Great Assigning!! And remember-"

Edge was seeing so much violent red, he barely had the faculties to register the end of the proceedings. All he knew was that he had to work that much harder to get his justice, to get his revenge.

But he would. Somehow. No matter what the cost.

**Notes for the Chapter:**

> I took this kinda dark and edgy because look -gestures- I wanted to.


	2. Meanwhile on Earth

**Summary for the Chapter:**

> Dib catches some of the Irken's transmission.
> 
> Meet the Cast of Team Earth-Swap.

**Notes for the Chapter:**

> Here is where the Humans and Underswap Monsters get introduced.
> 
> Just a chapter to establish relationships...
> 
> For those unfamiliar: Underswap Sans is called Blue, and Underswap Papyrus is called Stretch.

_"The Universe will be ours for the taking! It's only a matter of time before all of the races of the universe serve the Irken Empire!!"_

_"I'll have them serve me curly fries..."_

"They're coming..." Dib whispered, clutching his headphones to the side of his head. He could barely believe it, but it was true! He heard them!! Whoever ' _they_ ' were. He took off the headphones, standing up from where he had been curled up in front of his equipment, overwhelmed by the magnitude of his discovery.

Then Dib was racing down from the roof, taking the quickest shortcut he knew back into the house (which landed him in the kitchen sink, soaking himself in dirty dish water, not that he honestly cared _now_ ). "They're _coming_!"

Dib hadn't meant for it to happen, but when he landed in the sink, he splashed the person who had at that moment been cleaning the dishes. Blue (a Monster, a real, live, honest to god creature of magic, a skeleton monster that was not to be confused with an undead skeleton in the least, it was so cool, he was so cool) flinched from the soapy suds, blocking the spray from getting in his sockets with his gloved hands. "GOOD MORNING, DIBROMIDE!"

"Uh, morning Bl-" Dib yelped as he was picked up out of the sink, then placed gently back down on the floor, by Blue. Blue was short for a monster, but he still had a few inches on Dib, and the kind of core strength that far more muscular creatures stood to envy.

Dib still found his little paranormal investigator heart trembling in glee when he thought about how his new roommate actually worked! Maybe he could convince Blue to let him hook him up to a few sensors and then have him do his weight lifting routine and-

_No! Wait! Focus! Amazing magical friend later! Threat of alien invasion now!_

A quick scan of the room showed Dib that his father was home for once (a feat, given that Professor Membrane, the worlds greatest scientist, had been a chronic workaholic even before Monsters came out of the Underground, even before he dedicated 50% of his life to proving that they were made of a new kind of science and that magic was not, in fact, real). Dib darted over and tugged on his labcoat. "Dad! They're coming! I actually heard them!! I was up on the roof, and I heard this transmission was coming through-"

Dad shushed at him, holding up- or in this case, down- one hand in supplication as he looked at Dib over his shoulder. His safety goggles gleamed in the kitchen's ftoescent light. "Not now son, I'm making..." He leaned back over the counter, and loud, powerful sparks of electricity crackled in the air around and above his hands. Then he held up his creation dramatically, proclaiming his achievement with the same level of pride he did any other: "Toast!!"

Dib stared at his father, his father's reinvented toast, then his father again: he was reminded that this was the man that denied the existence of magic in the same breath that he told his children that their new babysitter was going to be an animated skeleton creature. He felt the weight of Blue's gaze on him, the brief buzz of projected sympathy and pity and understanding that Dib only ever felt like he got from Blue and his brother.

A noise brought Dib's attention to his little sister, who was drinking a juicebox. He spun around and ran from his father in favor of sharing with her instead. "Gaz! They're coming! They really are!!"

Gaz glared at him through the slits of her eyes, and Dib got the feeling she was in a bad mood (which wasn't unusual, but never boded well for the target of her ire). " _Who's_ coming, _Dib_?"

"I don't know!"

"ARE THEY COMING FOR BREAKFAST?" Blue asked as he began mopping up the excess water that Dib had accidentally spread all over the floor.

"No, no-"

"LUNCH? AND HOW MANY? DO THEY HAVE ANY FOOD ALLERGIES?"

"No, they're aliens!" Dib couldn't hide his building frustration. "They're not coming _over_ , they're _coming_ to take over the world and enslave humanity! And probably monsterkind too, I think. But also all of humanity!"

"Oh, my poor insane son..." Dib heard his father sigh. "As I explained before, S4-"

"BLUE IS FINE, DOCTOR. S4 IS WHAT MY FATHER CALLS ME." Blue corrected, as cheerful as always. His eyelights (amazing light-emitting orbs that moved and changed shape in his sockets) shifted from bright sky-blue starry shapes, to simple white ovals, which made Dib think he was somehow less happy than his voice would have him try to appear.

"Yes! As I explained, my poor boychild has an unfortunate case of _insanity_." Dad gesticulated along with his dynamic inflection. Dib always admired his father for many things, showmanship and presence being high on the list. "He has yet to accept and come to appreciate Real Science."

Blue looked between Dad and Dib. "...OF COURSE. IT COULD NOT POSSIBLY BE ANYTHING ELSE, COULD IT, DR. MEMBRANE?" The subtle sarcasm in his otherwise cheerful inflection gave Dib more validation than he thought could physically be felt by a single human being.

"I do hope his insistence on calling you _'magic'_ isn't overly distressing, S4. I assure you that I do my very best to dissuade such language, but you yourself may have to reinforce preferred terminology in my absence."

"IT IS QUITE ALRIGHT, PROFESSOR," Blue assured. "DIBROMIDE AND GAZLENE ARE A PLEASURE."

"That is always good to hear! Well, I must be off to work. See that the kids get to school on time, won't you?" With a click of Dad's heels, his jetboots kicked into gear. He flew briskly out of the window, leaving Dib, Gaz, and Blue behind in the kitchen.

Blue took a deep breath (although Dib still didn't know why he needed to breathe, given he was a _skeleton_ without any organs, and also _magical_ , and he was so cool and Dib was the luckiest kid ever to have a magical skeleton monster as a nanny like _how cool was that_ ), held it for one second, two, then let it out slow, all while maintaining his persistent smile. "WELP!! IT SEEMS YOUR FATHER FORGOT THAT THERE IS NO SCHOOL ON SUNDAYS!" He chuckled, putting the mop back in the corner. "WHAT DO YOU BOTH WANT FOR BREAKFAST?"

"Waffle," Gaz demanded. "And also we're out of soda."

"I WILL ADD IT TO THE LIST FOR WHEN I GO SHOPPING THIS AFTERNOON," Blue assured, setting to work on making waffles. "WILL JUICE BE ACCEPTABLE FOR LUNCH?"

"I... _guess_ so," Gaz sullenly agreed, giving Dib the stink eye.

"Why are you looking at me like that?"

"Don't pretend like you don't know, soda-drinker."

"Hey, I don't even drink that stuff!"

"Lier!"

"Am not!"

Dib actually had drunk the last soda last night; he'd needed the caffeine to stay up listening to radio waves from outer space. He certainly wasn't going to admit it to Gaz, though, not when he might be able to get away with it. If she _knew_ he did it, and that was the thing that had made her angry, then admitting to it was only going to get him beat up (or worse).

Being on the wrong side of Gaz's sensibilities was a fate worse than death.

"NOW, NOW," Blue cut in over his shoulder, flipping a fluffy waffle off the iron and onto a plate. "IF YOU FORGIVE YOUR BROTHER FOR THE SODA, I'LL ADD SOME CHOCOLATE CHIPS TO SOME OF YOUR WAFFLES!"

Gaz considered this. "...deal."

Blue was the coolest, in Dib's personal opinion.

* * *

Breakfast was delicious. As long as he had a recipe to follow, Blue was an excellent cook. Even outside being a paranormal investigator's dream come true, Blue was one of the best things to ever happen to Dib. The whole Swollen Eyeball was incredibly jealous of all the Monster information that Dib was able to supply thanks to Blue and his brother.

Gaz got her chocolate chip waffles and Dib wasn't terrorized. She did, however, give him one last leer before wandering off to play her Game Slave in the livingroom.

Dib sat in the kitchen and watched Blue clean up, slurping his orange juice quietly as he thought about how he was going to save the world from the incoming alien invasion. "So, Blue, about the Aliens-"

"YES?"

"You're really strong, right?"

"I AM INDEED!" Blue paused in his cleaning to strike a pose, as if showing off muscles he didn't actually have. His face was glowing faintly, in what Dib was starting to think was his equivalent to a blush.

"So, when I find the _alien scum_ , you can jump in and beat them up no problem!!" That made things _so much easier!_ "With my brains and your super magic powers, we'll be unstoppable!!"

"WELL, ABOUT THAT..."

_What?!_

"JUST BECAUSE I CAN ABSOLUTELY BEAT ANYONE UP, EVEN ALIENS THAT MAY OR MAY NOT BE COMING OVER FOR DINNER, THAT DOES NOT MEAN THAT I _SHOULD._ "

" _Of course it does!!_ "

Blue shook his head. "NO, IT DOES NOT, YOUNG HUMAN FRIEND."

"How else are we going to save the world?!" Dib demanded, hating how his voice cracked.

"OBVIOUSLY, WE MAKE FRIENDS WITH OUR NEW ALIEN VISITORS AND TEACH THEM THAT VIOLENCE IS NOT THE ANSWER!!"

Dib felt his arm cramp from the strain of not smacking himself in the face. "We can't _'make friends'_ with alien invaders bent on world domination?!"

"whose doing what now?" Came a voice from the kitchen doorway.

"GOOD MORNING, BROTHER!" Blue chirped. "DIBROMIDE IS EXPECTING SOME NEW FRIENDS TO VISIT LATER!"

"new friends huh?" The speaker pulled out the chair next to Dib and slumped into it. Stretch, Blue's younger brother, was another skeleton Monster, although he was significantly taller than Blue, with more defined, pointy cheekbones and smaller eye sockets.

"No, they're _aliens_ and they're _evil_!!" Dib was starting to get frustrated. Why did nobody believe him?!

"eh, how do ya know? have ya met them yet? maybe..." Stretch's grin quirked up in a way that normal bone wouldn't be able to do, the expression even reaching his eye sockets.

Dib was _so fascinated_ by Monsters and how they worked, it was so tempting to just forget about the alien scourge and focus all his time on his studies of Monsters...

"STRETCH-!!" Blue said in that tone that was definitely some kind of warning.

But Dib knew if he didn't take the alien threat seriously, nobody would. Even knowing that, it was so terribly _frustrating_ to be dismissed no matter what proof he tried to show the people around him...

"they're actually..."

"DON'T YOU DARE!!"

"pretty _stellar!!_ "

Dib looked over at Stretch, sipping his juice. He didn't quite understand why Blue looked so irritated. After all, just because Stretch was objectively wrong about aliens being st-

_Oh._

Dib snorted. "That joke was terrible."

"got ya both smiling."

"AND WE HATE IT, ISN'T THAT RIGHT, DIBROMIDE?"

Dib looked down at his juice. The pun was kinda lame, but... it was nice to feel like Stretch was trying to cheer him up. And even if they didn't see the urgency of the situation, Blue and Stretch still seemed to believe him... That was more than he got from even Dad.

"cmon, kiddo," Stretch clapped Dib on the shoulder. "wanna watch your sister make soldier of dooty fanboys ragequit?"

"...Yeah, ok. But we're still watching Mysterious Mysteries later, right?"

"sure are."

Blue set a plate of waffles in front of Stretch, along with a bottle of honey. "DON'T FORGET TO EAT YOUR BREAKFAST. WATCH THE KIDS WHILE I AM OUT SHOPPING FOR THE WEEK, WOULD YOU?"

"no problem, bro."

Dib let himself be distracted by the fascinating conundrum of how a skeleton monster ate waffles. The aliens could wait. For now.

* * *

Undyne nervously fumbled with her glasses, adjusting how they sat on her face. Her nearly nonexistent nosebridge always made keeping them upright difficult, so much so to the point that she tended to cheat with Green Magic. Even then, though, holding onto inanimate objects tended to be imperfect, and they got jostled just the same. At the very least, it gave her something to do with her hands while she waited.

Dr Wingdings, the de-facto royal scientist of monsterkind (and her rather exacting superior), paced back and forth along an arbitrary path from one side of the lab to the other, as he had been doing for over an hour. He came to a stop near the wall, checked his watch, scowled, and then whipped around to resume his pacing.

Undyne averted her eyes, looking down at the armful of notes and files she carried for Dings' convenience. Since coming to the surface, Dings had started making an effort to write in a more conventional font as opposed to his namesake, although there were still notes messily scrawled here and there across some of the pages in the inconvenient symbols that she had been made to learn to read early into her internship.

Undyne wasn't the only one to notice that Ding's sudden change of heart about his font corresponded suspiciously with his partnership with Professor Membrane.

The Royal Scientist completed his pacing loop again, and checked his watch once more. His soft, round face, which normally sported a mask of a smile, was closed off and cold, his mouth pressed into a thin, displeased line that eerily matched the cracks that spanned from his eye sockets. Undyne, as his personal assistant, saw that expression more than most, and it never meant anything good.

At least, it never had Underground.

Today, although she was still too cautious to mention it, Undyne thought that perhaps it meant something amazing.

"What is Professor Membrane's usual schedule?" Wingdings asked.

Undyne nearly jumped out of her scales, not expecting to be spoken to yet. She scrambled to pull out the notes regarding that very information, grateful for her gloves protecting her hands from the paper, and the paper from her clammy hands. "H- He usually arrives in the u-upper labs for briefings at s-six a.m.-"

"Then explain to me why it is Six-Twenty-Nine, and he is nowhere to be seen?"

Undyne gulped. Part of her wanted to snap that it wasn't _her_ fault his boyfriend was standing him up, and if he'd just kiss him already maybe his boner wouldn't hurt so bad, but she didn't have the guts to say that to his face.

Even if she really, _really_ wanted to.

"I-it could be that he has returned to his h-home for i-inspection..." Undyne suggested. "I-it isn't on the schedule, but.... he sometimes goes there... checking on the k-kids... and- and on those days, his normal routine is pushed back b-by about half an hour..?"

Dr Wingdings leveled her with the same cool, impassive expression that Undyne would have expected if she had actually spoken her mind, and a part of her began to panic, wondering if maybe she'd thought out loud again. Dings held her in his gaze, as if his very attention was a magic spell, as if her soul was caught and held fast by the very idea of displeasing him.

It would have been so fucking cool if she wasn't terrified of being fired.

"...Ah. Yes. I knew that," Dings admitted, voice going quieter. "Of course. I saw him at the domicile this morning."

Undyne bit her lip to keep from screaming at him: the idiot lived with the man and was asking _her_ what his fucking schedule was?! Dings was a genius, admirable from many angles, but he had no idea how to person. Neither did Professor Membrane, but between the two of them, Undyne thought the Professor tried a little bit harder than Dings.

Not that Undyne thought Dings didn't _try_ , so much as just colossally suck at it. Especially with Stretch, who had always been less forgiving if Ding's eccentricities.

It was weird working for your bestie's old man and seeing both perspectives.

A high pitched rushing noise echoed through the lab, and Undyne saw Dings' mood change in real time. His scowl became a delighted smile, face and eyelights brightening in a hue of colors. Just as Professor Membrane floated through the window to land on a designated landing pad that had been installed on the floor, Dings walked up to greet him. "Good morning, Professor!"

"And good morning to you, Doctor!" Membrane replied, kicking a bit of carbonized debris off his boots by tapping the steel toes on the landing pad floor, one after another. "How was your inspection of experiment TS395?"

"Responding promisingly to audio-visual cues," Dings assured. "And your latest experiment?"

"Project SuperToast has made remarkable progress!" Membrane pulled out a bit of nondescript toast. "See! I am excited to test it on the mice."

"I have exactly what we need then," Dings purred. "I just so happen to have a large colony of mice that are a mixture of monster and material mice! We can easily portion them off for control groups and compare the effects!"

"What an excellent idea, Doctor! Onward! To the mice!!"

Undyne followed behind them, pretending not to notice that Dings, the ever antisocial Dr Wingdings, was walking suspiciously close to Membrane's side.

**Notes for the Chapter:**

> Lookie there at that background Swap Gaster/Professor Membrane ship I'm playing with hehehheehehehheehe-


	3. Proximity Warning

**Summary for the Chapter:**

> Zim, Edge, and their new GIR unit arrive on earth and establish their base.
> 
> That's it, that's the chapter.

**Notes for the Chapter:**

> A lot of "going over the literal episode" here. I'm so sorry to everyone intimately familiar with the IZ cartoon, because this will probably bore you to tears until the very end scene. XD

Edge kept his eyelights forward as he flew the spaceship he had been flying for what felt like an eternity, although he knew it to be no more than day. Dr Gaster and Dr Alphys had incorporated 'shortcut' warp technology into the already sophisticated Irken tech left behind after OID1, which made the journey to his and Zim's glorified banishment that much smoother.

The Garbage Information Retrieval unit that Tallest Red and Purple had given to Zim made the journey unbearably torturous. There was something about its incessant, unbroken rendition of 'The Doom Song' (patent no doubt pending) that made Edge think being subjected to its like was some sort of warcrime.

If it wasn't a war crime, when Edge executed his coup, he was going to make it one after a day of subjecting Tallest Red to the experience.

At the very least, it seemed that Zim agreed. Swallowing back saliva, the tiny Irken rasped out what was the closest thing to a plea that Edge had ever heard come out of his mouth from where he sat in Edge's lap. "GIR, would you _please_ stop singing??"

The robot menace, self proclaimed as GIR, continued whatever nonsense its malfunctioning internal mechanisms seemed to believe qualified as music. It was only Edge's preternatural self control that kept him from flinging the thing out of the ship.

Zim seemed to have less such control, as he began to reach for GIR with grasping hands, brimming with intent to strangle the life (or at least the voice) out of the mechanical pest. He was interrupted by the ship, which finally had an update.

"PROXIMITY WARNING:" announced the basic computer, "PLANET AHEAD."

As if Edge couldn't see the fucking thing right in front of them through the window.

Edge might have been in a bad mood.

Zim sat up ramrod straight, turning to face forward. "GIR!! We're here! We're finally _here_!!" He stroked the monitor as if in reverence, genuine glee making his stupid little antenna quiver.

GIR held up a finger, pausing its endless musical blasphemy for the first time. After a breath, it _continued_. " _Doom doom di-doom doom-doom-doom_ -" And Edge really was about to crack the last reserves of his rapidly depleting patience before- " _The end!_ Ooh, what's that?"

Only proving the damned thing had been paying no attention. Edge despised the little trash heap with a slow burning ire hot enough to melt steel. He was careful not to let that emotion run rampant, not while inside the only spaceship he had access to, the only way he could return home.

Strange: Edge had spent his entire life trying to leave, and now all he wanted was to go back.

"IT IS A PLANET CALLED 'EARTH'," Edge droned, having read over that information from the ship's scan. He was rather proud of having picked up how to read Irken script so quickly.

Edge didn't think about how much faster his brother would have done the same, given the chance.

"I was gonna say that!" Zim whined. The little shit slapped Edge's wrists, a silent demand to relinquish the ship's controls. Edge let go more out of shock than genuine compliance, giving Zim all the opportunity he needed to direct the ship himself.

There had been so little Intent to Hurt in those hands (not that Edge was particularly fragile, but still)...

"Now," Zim navigated the ship through the atmosphere , settling at an altitude with minimal turbulence. "I know you're new to being an Invader, Edge, so listen up! First off, we have to set up a base of operations."

GIR giggled.

Edge clenched his trembling fists, refraining from damaging his charge's precious property by the metaphorical skin of his teeth.

"Focus, GIR!! This is where _your_ advanced information gathering skills come in handy."

"Yes, my master!" GIR responded, its vocalization shifting to match that of the functional SIR Units from which it was modeled, the soft teal of its light fixtures (in its orbital implants and chest display both) briefly turning the standard crimson before going back again.

"GIR, you have to observe what these..." Zim glanced back down at the monitor quickly. "...'earthanoids' consider to be normal, then based on your observations we make our disguises. And our home."

"WITH ALL DO RESPECT," Edge growled through gritted teeth. "RELYING ON THE GIR UNIT WOULD BE LESS THAN OPTIMAL. A STANDARD MANUAL RECONNAISSANCE WOULD GIVE US FAR MORE ACCURATE-"

"Silence, minion!" Zim ordered. "GIR is the most advanced Information Retrieval Unit in the entire Irken Empire, and the Tallest entrusted such advanced technology to _me_ for this very reason!"

"YOU MUST KNOW THAT THOSE WERE LIES TO HIDE THE FACT THAT-"

"Who outranks whom in this cockpit, huh?! Me or you?!"

Edge really, _really_ didn't want to answer that.

"Well?! Don't make me tell 'Mom' on you!"

Heaving a great sigh, Edge forced himself to answer. "YOU DO, _PRINCE_ ZIM."

"That's _Invader_ Prince Zim, but you have the right idea."

Edge tried not to sigh his soul out as Zim sped over the planet's surface, ignoring the stupid laughter from the robot. How the Irken scum managed to make a robot so expressive without a soul, he would never know. He didn't honestly care at the moment either.

The ship, under Zim's direction, made a number of loops around what appeared to be a densely populated area, before coming in low between two buildings at the end of a cul-de-sac while screaming " _Here!_ We build _here!_ " at the top of his lungs. He parked the ship, and then jumped out to examine the area from the ground before the exhaust even dissipated from the engines. "Whoooo, that was easy..." He said, as if he were not speaking to himself in the dark of night on an enemy planet. "GIR! Edge! Get out here!"

The robot poked its head out of the ship, then gracelessly launched itself upward, only to bounce off the outside of the ship's hull and roll down like so much debris out into the open beside Zim.

Edge resisted the order at first, not just because he was loathed to obey an Irken (even Zim), but because it was a stupid idea to waltz outside without even analyzing the limited data the robot had managed to gather.

" _Edge!_ I said get out here!"

Edge grit his teeth and climbed out of the cramped spaceship, dusting off his military uniform. He took a moment to crack the joints of his neck and spine, rolling his shoulders after being hunched down to fit in the ship of his new ward. He could admit it felt good to stretch his bones.

A quick vault had Edge down on the ground with Zim, looking around at surrounding area.

"No, hurry GIR, what did you learn?" Zim asked, returning his focus to the precious trash robot.

"I saw a squirrel!" GIR answered.

Zim and Edge both stared at the little robot.

"It was doing like this," and then GIR began to make a number of clicking and munching noises, posing with its hands in front it.

"Concentrate, GIR," Zim snapped, although with less bite than Edge thought appropriate. "It is time for disguises."

"I want to be a mongoose," GIR immediately replied.

"OF COURSE YOU DO," Edge muttered under his breath, having just looked up what a squirrel and a mongoose were on his datapad.

Zim shushed Edge, glaring up at him as if _he_ had been the one screaming and making foreign animal noises. "We have to be quiet!"

Edge inclined his head to his prince, resuming his work looking through the data that GIR had gathered during their brief scan. Most of it was nonsensical and irrelevant, but what stood out to Edge was the abundance of MAGIC in the atmosphere. He had been worried he himself was soaking the air in it, but no: Earth was _dripping_ in magic.

And with levels like this, it could only mean that Monsters were on the planet, and flourishing. Edge, at least, would need very little in terms of a disguise. A bit more data and he could simply change his garments to fit in. It may do him good to mask his stats as well, but he tended to do so anyway, and only a Judge would be able to see through his defenses in any meaningful way.

Such talented creatures were so rare, Edge doubted very much there was even one on the planet.

As Edge finished his analysis, he felt a pressure on his leg. He looked down to see Zim trying to push him towards the pod attached to the ship that made disguises ( _trying_ being the key word there, as he was less than capable of moving Edge when he did not want to be moved.

"WHAT?" Edge tried not to demand, but his voice came out sharp with his ire.

"Get your disguise on!" Zim hissed. "I already picked the perfect one!"

"I DO NOT NEED-"

"I am Zim! Obey me, guard minion!"

Edge was starting to feel old with how much sighing he had started doing. Unfortunately, he needed Zim alive and in good health if his plans were to work, _especially_ now, _spitefully_ now. So, grudgingly, he went and sat in the pod to let it do as Zim bid.

Edge had seen what Zim considered an appropriate disguise: All he wore was a wig and contacts, while the GIR unite was in a green animal suit with a prominent zipper. He could only imagine that his choice for himself would be equally ridiculous.

When Edge was allowed to crawl out of the pod, brushing fumes from his person, he found himself wearing a pink apron. Just- Just a frilly pink apron not unlike the ones he had seen Mettaton wear, tied overtop his armor.

"Ingenious!" Zim cried out, posing dramatically. "Now, all we need is a home. Let's see..." The little pest pulled a strange item out of his inventory, which opened up into a holo-pad with a stylus. He started drawing on it as he muttered, "Some windows, a couple of little animal things in front. _THERE!_ " He popped the stylus back into the device, compressed it again, and Edge watched as one end of the tube became a _drill_. Zim pressed the drill end into the ground between the two houses, and it slowly made its way underground. "Hide!" He yelled, running out to get behind a small red fixture.

The GIR unit ran after him, squeaking with every step, until it jumped into the road behind Zim and skid to a halt. Edge opted for something less dramatic, walking calmly out onto the sidewalk to stand next to Zim.

"And _be quiet!_ " Zim hissed. "We cant afford to make a sound!"

That proved to be a futile order. Advanced as Irken technology was, it was not _quiet_. The little device grew and expanded out into a rather aesthetically weak looking dwelling, which stood out in bright colors compared to the drab hues of its neighbors. The loud siren noises aside, Zim's newly grown base looked inorganic in the way a dollhouse looked inorganic, with sharp angles in some places and no texture at all in others. Even the yard was fake, lacking any scent or natural motion that most living organisms would have, that the ones in the yards around them _did_ have.

As Zim picked up the leash attached to GIR, which somehow turned off the alarm noises the house was making, Edge made a note to incorporate more organic material into their base: it would not do to be found out over such an easily corrected mistake.

Edge followed Zim and GIR into the house, ignoring the stares from the 'Earthanoids' that were to become their neighbors, and closed the door quietly behind them.

"Wooooo! Step one went _smoothly!_ " Zim sighed, as if he hadn't bungled every step since entering the Earth's atmosphere. Edge let it go: they had a base now, and once Zim was off doing whatever the hell it was he wanted to do, Edge could begin his own plans.

Zim climbed into what looked like a trashcan, which was apparently a disguised elevator. Edge watched him disappear down into the depths of the base to do only stars knew what.

This was Edge's opportunity. "COMPUTER: TAKE ME TO THE MAIN SYSTEM CORE."

A panel under Edge's feet opened, and he was lowered deeper into the mess of a base he would be spending an indeterminate amount of time in. Edge was already struggling with the sheer disorganization of the 'floorplan' from just his initial observations, and he knew the base was going to be massive.

The Main System Core was a large oval room deep at the heart of the base. It was lined with a large conduit cable thicker around than Edge's entire body, and at the very center was a module where the AI Brain that controlled the entire 'house' was connected into the system. Edge had heard some of the scientists in passing talk about how there was no way in hell such brains were entirely synthetic, but as far as Edge was concerned, it was likely a blessing that organic biotechnology was already integrated.

Edge took his place at the control module, staring at the perfectly average AI Brain. He then pulled out the gift he had been given by Dr Alphys, a similarly designed interface which held in its container, not a brain, but a SOUL. It was a simple procedure to remove the standard AI Brain, and instead insert the SOUL in its place. Ten seconds, a few buttons; the brain was out, the SOUL was in.

It felt too easy, too anticlimactic.

Edge swallowed down a lump in his nonexistent throat. "COMPUTER: STATUS REPORT."

For a long moment, nothing happened. Edge resisted the urge to claw at the console. "COMPUTER: STATUS!"

Still, still silence.

The little white soul, covered in black crust here and there with purple smoking edges, bobbed quietly in its container.

"COMPUTER-"

" _th' fuck is goin' on here?!_ "

Edge sagged to the floor of the platform, resting his head against the console. _His voice_. A bit mechanical, a bit distorted, but the cadence and timbre was unmistakable. It worked, it _actually worked_.

" _boss?!_ th' _fuck_ are ya _wearin'?!_ "

Edge actually started laughing. He couldn't help himself.

"th' fuck is goin' on?!"

"RED, YOU-" Edge had no idea how to explain everything. How was he supposed to tell his brother he was dead, but not, because Edge was selfish and couldn't bear to be alone? "YOU ARE NOW THE CENTRAL CONTROL CENTER FOR AN ENTIRE BUILDING."

"...wut, like an ai?"

"YES. EXCEPT YOU ARE... YOU..." Or Edge hoped it was him. Prayed. There would be hell to pay if it wasn't.

"...so th' fucker _did_ shank me, huh..." The computer, RED, muttered. "fuckin' perfect..."

"CAN YOU ACCESS THE COMPUTER DATA?"

"hold th' fuck on, i'm still figurin' out what all these new bodyparts fuckin' do-" RED snapped. "...thats th' cams... th' fuck 'r these things outside? this house is my new body? it's stupid lookin' as shit- izzat _zim_?!"

"YES."

"...we're fucked, ain't we?"

"FOR NOW." Edge stood back up, smoothing out his stupid apron. "COMPUTER: ACTIVATE PARENTAL CONTROLS ON THE CENTRAL CONTROL ROOM. VOICE ACTIVATION REQUIRED. REGISTER: INVADER EDGE."

"irken tech sucks, 'n i gotta speed program a parental control- ok. done. nobody has access but you, boss."

That was one less thing to worry about. Edge did _not_ want Zim or the GIR unit getting anywhere near his brother's soul.

"now get in th' stupid pod elevator. our new prince is bitchin' about gettin' into a skool."

Edge let himself have a moment to groan as he stepped into the elevator. Earth was going to be hell.

But at least he still had some of RED left. Little mercies.

**Notes for the Chapter:**

> I did say I was a Sans simp, didnt i? I should have mentioned that somewhere. If I havent, I'm definitely a sans Simp, and theres no way in hell Underfell Sans doesnt have at least SOME role in an Underfell-prominent fic
> 
> also i love the idea of red fucking with zim at every turn and also having to suffer GIR all day
> 
> also also you can probably see where i have some i influences from [Tech Support](https://archiveofourown.org/works/25398691/chapters/61591555) By aug325 & CephalonGhost, who probably dont want self indulgent undertale crossovers linked as inspired by their amazing IZ fic that I highly recommend because their HCs are amazing and so is their brane/brain ship ok bye


	4. Meetings

**Summary for the Chapter:**

> The main characters meet, and the first episode ends.
> 
> Also GIR eats roses.

**Notes for the Chapter:**

> its the part MK super duper wanted and i can finally give it to her! here you go MK i hope you like it!! <3

Stretch chewed absently on the end of his lollipop, thinking over what Dib had been saying all day yesterday. Poor kid was so sure about what he'd been hearing... But honestly, Stretch could think of a ton of explanations for what Dib had actually heard: malicious prank by Gaz; stray radio signal; amplified baby monitor overhearing a really cheesy D&D game; Dings being an asshole; the list goes on. It was only at the very, very, _very very very_ bottom of that list that 'actual alien transmission' had itself a cramped little afterthought of a seat.

It wasn't good to admit that to him, of course: Dib already had a disgusting lack of support from his family, Stretch sure as hell wasn't going to drop him when he had no proof it wasn't exactly what the kid said it was.

Stretch still felt kinda scummy for not believing Dib which his whole soul, though, and the house felt too empty and too cramped all at once with everyone else out at work or school. Getting some air did Stretch more good than not.

Stretch loved walking around. Just. Loved it. He might have been into jogging in another life, one where he wasn't also lazy and had the stamina of a diseased goldfish. He found if he walked around enough, he'd find something interesting. Lately, he'd been following the adventures of this weird, mangy chihuahua that ate the neighborhood garbage. Stretch had been tracking it all over the suburban areas.

The last time Stretch saw the lil guy, it had been somewhere... around this cul-de-sac that was ordinary and somewhat uninteresting. Stretch wandered along until he reached the place.

The first thing that caught Stretch's attention was the extra house: either Stretch was very, very lost, or a brand new house had been erected overnight. Stretch was rather proud of his sense of direction, so he was rather certain it was the latter. Concerned, intrigued, and a few other adjectives that would have described the cat killed by curiosity, Stretch approached the new structure.

It was incredibly tacky, the kind of tacky that made Stretch love it instantly, despite himself: bright tertiary colors, doopy looking gnome lawn ornaments, and the front door looked like it belonged to a truck stop's men's bathroom. There were a few bags of soil, a tin watering can, two kinds of tiny shovels, and a pair of gardening gloves left on the front step.

Before Stretch could get any closer, the front door opened, and out walked a tall skeleton in a pink apron.

This normally wouldn't have meant anything significant, except that the guy was a _skeleton_ monster. Stretch knew a thing or two about skeleton monsters, one fun fact being that there were _only two on the entire planet_. Unless the guy was a very old zombie (which, given what he'd seen of the mall, isn't entirely out of the range of possibilities), he shouldn't be able to exist.

The skeleton set a tray of weird red flowers down on the step, then pulled off his red leather gloves, replacing them with the gardening gloves that had waited for him. Surveying the yard, he gave an aggravated sigh, then knelt in the grass and began the slow, methodical task of making a brand new flower bed up against the side of the house.

Stretch crept closer, keeping close to the wall of the neighboring building, peaking into the yard at the thing that shouldn't by all rights exist. Once Stretch got close enough, he narrowed his focus to CHECK the monster-

And then he was on his back, on the ground, pinned by BLUE magic so oppressive it made it hard to _breathe_. But he'd seen the stats- He'd seen-

That was definitely a monster.

And not just any monster: he was a monster with _LV._ Not a paltry accidental amount of LV either- a _metric fuck ton_ of LV. There was a serial killer in the neighborhood-

_There was a serial killer on top of Stretch with a jagged bone construct at his throat-_

"WHO ARE YOU?" The other monster demanded, crimson eyelights burning like hot coals in the pits of his sockets.

Stretch clawed at the pavement with the flats of his phalanges, struggling against the pressure of the BLUE magic bearing down on him. "s-stretch." Maybe if he kept talking, someone would come and help him.

There was a long, silent moment. "STRETCH..." The other repeated. "STRETCH..." Slower, savoring it. "I WILL REMEMBER THAT NAME."

The BLUE attach lessened its grip, although Stretch still struggled to sit upright (not that he wanted to try that with a magic knife in his face). Mind frantically trying to puzzle out a solution to a puzzle that was looking impossible, Stretch gave talking a shot. He was pretty good at talking. "a-and you? never seen you around before. got a name?"

The _thing_ above him continued to loom. "...EDGE."

"edge huh?" Stretch eased one of his hands into one of his pockets, hoping that his plan would work, hoping he still had some left after their little trip to the beach. "where ya from?"

Edge smirked. "FAR AWAY." He brought that weapon down lower, easing it between Stretch's throat and his jaw, tapping the flat against his vertebrae. Stretch flinched from the overwhelming buzz of foreign magic, of something so distinctly _other_ that it actually made his head spin. "WOULD YOU LIKE TO S-"

"E~~~~~~~d~~~~~~~g~~~~~~~e~~~~~~~!!!" Called a high pitched voice. "Haus says you has a carrot!"

Edge turned his head to look over his shoulder, pulling the weapon away from Stretch's fragile neck. "GET BACK IN THE _FUCKING_ HOUSE, GIR!" The fact that his voice in that moment was even _more_ aggressive and irritated than it had been while talking to Stretch did very little to assuage Stretch's concerns.

"But _I_ wants a carrot!! I wants it _so bad_!! What's a carrot?"

"HOW THE FUCK SHOULD I KNOW, _YOU'RE_ THE FUCKING-" He paused. Lowering his voice as he looked back at Stretch before returning his eyelights to the- the little green plush toy? in his doorway? "AHEM. DOG. YOU ARE THE DOG. OF COURSE YOU DO NOT KNOW WHAT A CARROT IS. BECAUSE YOU ARE THE-"

Stretch tensed his arm, waiting for the moment Edge looked back at him. As soon as he had his opening, Stretch yanked his arm out and threw the contents of his shorts' pocket into Edge's face. "pocket sand attack!"

As Stretch had hoped, the irritating granules got into Edge's sockets, disrupting the magic there and thus blinding him. The murderous fiend reared back, clutching at his face. Stretch scrambled to his feet and ran as fast as he could, rounding a corner before letting himself shortcut back to the safety of his bedroom.

Stretch collapsed onto his bed, clutching at his neck, where he could still feel the prickling from when that freak had touched his bare bones with his tainted magic. There was _absolutely_ something weird about that man, that house, and Stretch was going to figure out what.

Like hell Stretch was letting some unnatural murderous freak ruin his and his family's happy ending.

* * *

Edge stumbled back to his feet, splitting his attention between defensive awareness and getting the _fucking sand_ out of his skull. It wasn't the first time someone had thrown uncomfortable material into his sockets, and probably would not be the last, but it was damned effective at blinding him for a few minutes. Not that him being blind had ever been terribly useful for his enemies: Edge had slain more than a few would-be assassins who thought taking his sight would be enough to take his life. All it did was piss him off most of the time, make it so when he got his hands on the perpetrator, they wished for death long before they got it.

Edge was having very different thoughts about the last thing he saw before being assaulted by sand, however, very different thoughts indeed.

Edge heard the scrape of his prey escaping him, but he did not give chase. Edge had no need to give chase, not now. He had a face, a name, a scent: Stretch would not so easily escape his advances. Instead, Edge focused on shaking out the sand.

When Edge finally blinked his vision back, he saw what he already knew: Stretch was gone. Dismissing his weapon, Edge turned back to the house-

Only to see that his newly acquired biological earth decorations were missing significant volume and matter, as was one of his shovels. "GIR!! WHAT THE FUCK DID YOU DO TO MY ROSES?!"

"Your what?"

"THE FUCKING FLOWERS, GIR: WHAT THE FUCK DID YOU DO TO THEM?!"

"Oh, these?" The GIR unit picked up one of the few remaining plants, wiggled in front of its face, and then _ate it_ with neither prompting nor fanfare.

Edge hadn't even known the robot _could_ eat. He thought it ran on electricity, or batteries.

"...OF COURSE." Edge pinched the bridge of his nasal ridge, repressing the oncoming headache that was ruining what had been a good mood. He would have to procure more biological earth decorations for his biological earth decoration area, but doing so without funding again would be messy and risk what was now a Very Important Mission. Letting out a sigh (something Edge was growing more and more certain would be a daily occurrence at the very least), he picked his way back through the yard and gathered what remained of his biological earth decoration tools. "GET BACK IN THE FUCKING HOUSE." He snapped.

GIR gave Edge was settled for a salute, its stupid disguise squeaking inexplicably with the motion, before skipping back into the house. Edge followed, kicking the door shut behind him.

It was while Edge was storing his new tools for another day that he heard the rumble of his brother's voice over the intercom system. "...so what th' hell was that?"

"WHAT WAS WHAT?" Edge asked, although he had a pretty good idea what RED meant.

" _that,_ " RED insisted, lowering a monitor from somewhere up in the mess of wires they had for a ceiling. Edge was rather proud of how fast his brother's soul was adjusting to its new mechanical host. " _this._ "

It was a playback of footage from what had to have been a few minutes ago, shot from an angle that Edge thought must have come from one of the ugly garden decorations outside in the yard -- the stupid things must have been integrated into the base's security system, which would make replacing them with something more aesthetically appealing that much more difficult. The video started with Edge's head on one side of the screen, where he was bent over the dirt. Behind him, in the distance, was Stretch, watching from around the corner of the neighboring building.

Edge was legitimately amazed: Stretch was standing there for far longer than he had thought- the guy had talent in stealth.

It was cute.

Edge knew the moment the him on screen felt the CHECK, because Stretch immediately dropped to the ground, out of sight behind the stupid white picket fence that surrounded the perimeter. The Edge on the recording bounded over the fence, pinning Stretch with his body and weapon as much as with BLUE magic. The screen became fuzzy, the footage fast forwarding based on the speed with which GIR moved once he appeared in the corner. It returned to normal speed right before the Edge in the recording reared back, suffering from the sand attack (although that wasn't evident from the footage).

RED pulled the screen back into the abyss of the ceiling. "so lemme try this again: _th' hell was that?!_ "

Edge smirked. "OH. JUST A FORTUITOUS MEETING, IS ALL."

"wut?"

"Edge found a _carrot!_ " GIR screamed unhelpfully.

"I HAVE FOUND THE FIRST CREATURE TO EVER BE WORTHY OF MY GREAT AND TERRIBLE ATTENTION," Edge declared, smiling to himself. "WHICH OF COURSE MEANS I MUST NOW RESEARCH HOW THIS PATHETIC PLANET CUSTOMARILY WOOS ITS MATES."

There was silence save for the odd squeaking of the GIR unit's costume as it rolled around on the floor.

RED finally let out a long sigh. "you have _got_ t' be shittin' me."

"I KID YOU NOT." Edge assured. "AND I HAVE ALREADY DECIDED THE COLOR OF THE COLLAR I WILL HAVE HIM WEAR! IT SHALL MATCH MY EYELIGHTS. THE VIBRANT HUE WILL LOOK STUNNING ON SUCH UNMARRED IVORY."

"we're on a fuckin' mission-"

"WE ARE BANISHED."

"we'll, _my brand-spankin'-new memory banks_ say we're on a _goddamn mission,_ 'n neither this fuckin' mission nor yer fuckin' banishment include no sidequest t' get yer ass laid!"

"YOUR POINT?"

There was another pause. "...so we're gonna get yer ass laid." Edge could always count on RED's spite (and love of Edge, although even after his death, Edge would never utter that word in such context to RED's metaphorical face) to be stronger than anything else. "downloadin' all available data on earth's datin' customs."

"EXCELLENT."

* * *

Dib was out of breath when he finally, finally limped his way home. Chasing Zim's trail all the way to his base, ad-libbing an appropriate monologue, and then walking all the way home, had been more than enough cardio to wear his little 12-year-old body right out.

Or maybe he had just screamed too much.

He tested that theory by calling out to his housemates. "Gaz? Stretch? Blue? I'm home!"

There was no answering call, which meant Blue wasn't home. Dib sighed, coughing a bit as he kicked off his shoes to leave by the door. He headed to the kitchen to get a drink, then came back to sit on the couch next to his sister.

He drank half his juicebox before even attempting to talk again. "I said, I'm home."

Gaz grunted at him, refusing to look away from the screen of her Game Slave. Her thumbs were a blur as she worked at the buttons, the little speakers screeching with bitcrushed explosion noises and musical beeping.

"I did it, Gaz! I did it! I found a real live, honest to goodness _alien_! He goes to our school, and he has a flying dog! And I tracked him all the way to his house where he already has a monster enslaved to do his bidding and-"

"If your don't shut up with your distracting monologue I'll make you wish you never had teeth."

Dib shut up immediately, rolling his eyes and getting up again. Maybe Stretch was home. Stretch at least _listened_ to him.

Out of some petty spite, Dib swung back to the kitchen to take one of Gaz' precious sodas before sneaking back upstairs to knock on the skeleton monster's bedroom door. "Stretch? You home? I'm home! And I found the alien!!"

"it's open." Stretch called absently.

Dib took that as an invitation, turning the doorknob and stepping into the room. Stretch's room was usually a mess of discarded dirty clothes and empty honey bottles. His mattress never kept its sheets on for long, although Dib knew Blue went in there once a month to tidy up and make the bed like he did every other room. Dib wasn't particularly surprised by the empty donut box spinning around in a small tornado with a bunch of other miscellaneous trash.

What made Dib pause was the unusual scattering of machine parts all over the floor, leaving a trail of nuts, bolts, and sheet metal right to where Stretch was sitting cross-legged in the middle of the room, bent over what looked like some kind of homemade drone.

Dib shook his head: Stretch was just as eccentric as anyone else in the house, and him starting some random project wasn't completely unheard of. Dib's discovery was a bit more important. "Stretch! You're probably not going to believe this, but I found one! I found an _actual alien!_ Right here on Earth!" he picked his way around the scattered junk, careful not to step on anything. "We were about to start class when Ms Bitters suddenly got a phone call that made her even more bitter than usual, and then this _literal alien_ with no ears and green skin and this weird metal backpack just _walked into class_ and started pretending he was human! Just walked right in! Skin condition, my head! And he turned all the other kids against me despite my best efforts! They all think I'm crazy now because of him!"

"didn't they all think you were crazy before?" Stretch asked, proving at least he was paying partial attention to what Dib was saying. Dib was never going to get used to someone actually listening to him. It was a good feeling.

He also was never going to get used to how cool magic was, seeing Stretch levitate a wrench into his hand from across the room, sticking his tongue out as he started using it- _how does a skeleton have a tongue_ , is it made of ectoplasm?! Dib tried to imagine a rough schematic for how to scan that new phenomena, maybe with a little clip he could attach with wires for gathering data on- _no, wait, focus- the alien!_

"Well, yes, but now they think I'm even _more_ crazy! And it makes no sense because they _all saw Zim right there in class!!_ Like, literally right there!! They talked to him! How can they- how-" Dib let himself make a frustrated noise, kicking a dirty sweater and a metal pipe to one side so he could sit down on the floor with Stretch. "I don't know what he did but he's somehow fooling everyone! But he isn't fooling me! I almost caught him after skool, too! Remember those alien sleep cuffs I got in the mail? I luckily had them in my pocket today and I almost got him in them! I _almost had him!_ But then there were these dogs and- and then he called his flying robot dog and flew away! But that was _his_ mistake, see! 'Cuz the robot dog left an exhaust trail and it led me _right to his base!_ Which looks so dumb and fake, like the door looks like it came from the mall bathroom and there aren't even any flowers in the flower bed and-"

"wait, a bathroom door?" Stretch looked up from his drone. "was the house all pointy with weird chibi gnomes in the yard?"

"Yes! One of the gnomes shot _lasers_ out of its eyes and disintegrated my handcuffs!" Dib waved his empty hand, remembering how it felt for the metal to fall to dusty pieces between his fingers. There was still a soot stain! "...Wait, how did you guess?"

"was there a tall skeleton monster there?" Stretch's voice almost sounded urgent.

"Uh... yeah? I saw him when Zim ran into the house."

"oh my god, he's an _alien_."

"I knew you wouldn't- wait-" Dib dropped his thankfully empty juicebox. "You- you _really believe me_?! Wait, how did you know-?!"

Stretch looked away, a subtle shift in the voids of his sockets like he was averting his gaze. "i, uh, i stumbled into meeting the guy. he's- look, kiddo, he's real bad news. the kind of bad new we should really, _really_ be reporting to the police but-"

"But? But what?!"

Stretch scratched the back of his head. "the only proof i have is my word. and, while i have a little bit of pull, the guy i have to report to for that to be taken seriously? he-"

"You mean Dr Wingdings?" Dib asked, putting a few puzzle pieces together in his head. Stretch was always filling out little forms for Dr Dings, but he never looked happy about it.

"...yeah. him." Stretch sounded the same kind of unhappy he looked when he was filling out those forms. "if i told dings what i knew, he'd believe me, no question... but he'd probably not pass that information along how he should."

"Why not?! If he believes you when you say their aliens-"

"because dings is a d- a-" Stretch stumbled over his words, still looking that kind of unhappy he got around his dad. "he's more likely to try to use them, or even help them just to see what he could learn, than he would be in trying to stop them. it's... complicated."

Dib grit his teeth. It was just his luck. "So what do we do? If we can't go through Dr Dings, and we _definitely_ can't go through my dad-" Dad would just call him insane again, maybe even send him back to the Crazy House for Boys. "-then... then we'll just have to find proof that the Swollen Eyeball and- and the police and Mysterious Mysteries will accept! We'll show them all!"

"thats the idea, kiddo," Stretch hummed, patting the little drone. "we'll get 'em. But ya gotta promise me something."

"Anything!" Dib would do anything to have someone whole ham on his side in this!

"yanno how serious i take promises, so i need ya to take this promise super serious, ok?"

"Yeah!"

Stretch put a hand on Dib's shoulder, giving it a gentle squeeze. "that tall skeleton guy? don't try and mess with him, ok? you leave him to me. promise?"

Dib nodded fervently. "Ok! Divide and conquer! I'll get Zim, and you get the tall guy!"

Dib was so excited! He was gonna show the whole world that aliens were _real!_ Like, really real! And Stretch was gonna help!!

This was the best!

* * *

It was two days later before, while Zim was at skool, RED finally announced: "download complete. earth matin' customs data analyzed. come get yer shit, boss."

Edge stood up from where he had been scrubbing away greasy filth that GIR had tracked into the house. "ABOUT FUCKING TIME!"

"shut the fuck up, asshole," RED said, and Edge had to fight down the smile at that familiar hint of fondness in the insult. "ya got any fuckin' idea how much goddamn porn i had t' sort through?!"

"NOT ENOUGH TO EVER SATISFY YOU, I AM SURE."

"smartass. summary pdf's in yer datapad. now downloadin' some fuckin' videogames. bein' a computer is _boring_."

"YOU POOR THING. ALIVE AFTER AN EXECUTION AND UNABLE TO GET SHITFACED ON ALIEN SWILL." Edge missed this. He missed the banter that his brother brought into his life.

"i'll figure out how t' get drunk eventually," RED assured him. "i fuckin' need it after processin' all this stupid mindless cartoon bullshit 'n babysittin' this defective bot."

Edge looked over at where the GIR unit was sitting on the couch, staring unblinking at the monitor playing one of those very entertainment programs. As far as Edge and RED had figured out, it was one of the few things that would reliably keep GIR's attention for more than 30 seconds.

Such a shame it was mind numbing and made both RED and Edge want to kill something, if only so its dying scream would drown out the stupid music.

Edge turned his focus to the data pad, scanning through the PDF of earth courtship rituals. After some time studying, Edge was already formulating a plan.

Gift giving, especially the gift of a valuable rock, was customary in the local subculture. What rock was more valuable than a _planet?_

**Notes for the Chapter:**

> And now if i ever wanna write IZ/undertale shit i have an established plot to fuck around with
> 
> thanks again MK <3
> 
> god i could have so much fun playing with shared loves of tacos, antisocial tendencies, and honey between the respective pairs this group of characters, plus the membrane/dings ship, plus just... AAAAAAAA its dumb but it could be so much fun <3


End file.
